The last chapter of Jesmyn Ward’s memoir, “Men We Reaped,” begins with a litany of statistics “about what it means to be Black and poor in the south.” The numbers mount like burdens on an already-bent back: high rates of poverty, incarceration and illiteracy, low rankings in education and standard of living.

Each one bows the back a little farther to the ground; each one strips a little more from the soul.

By this point in her book, Ward has already laid bare the human toll of what being poor and Black in Mississippi meant for her and her family. It meant five young men — friends, cousins, boyfriends, brothers — cut down by drugs, violence, depression and just plain bad luck in the space of four years. It meant women left behind to scrape out a living, to hold wounded families together, to nurse their own regrets and sorrows and shriveled dreams.

The numbers, Ward notes, simply “bear fruit to the reality.” They also bear witness to a truth that stretches beyond her circle of family and friends, beyond the confines of her hometown of DeLisle, beyond the borders of Mississippi and its specter of racism and segregation.

It is the truth of what it means to be poor and black in America, in Chicago and Camden, N.J.; in Jasper, Texas, and Sanford, Fla.

The truth of what it is to be told, as Ward was by her affluent, white classmates in the private Episcopal school she attended, that your life has no value. “I was so depressed by the subtext I felt, so depressed I was silenced, because the message was always the same: You’re Black. You’re less than White. And then, at the heart of it: You’re less than human.”

The message — insidious and insistent — feeds into a sense of inevitability and defeat that preys on the men of DeLisle, nicknamed Wolf Town by early settlers.

“We tried to outpace the thing that chased us, that said: You are nothing,” writes Ward, whose 2011 novel about Hurricane Katrina, “Salvage the Bones,” won the National Book Award.

“We tried to ignore it, but sometimes we caught ourselves repeating what history said, mumbling along, brainwashed: I am nothing. We drank too much, smoked too much, were abusive to ourselves, to each other. We were bewildered. There is a great darkness bearing down on our lives, and no one acknowledges it.”

That darkness pervades the book, a powerful and wrenching elegy to the men Ward knew and loved and lost, including her younger brother, Joshua, who was killed by a drunken driver. Their deaths leave a pall of grief that never ebbs, Ward writes. “Grief scabs over like my scars and pulls into new, painful configurations as it knits.”

It was that grief, that need to make some sort of sense out of the deaths that seemed to stalk her world like a prowling wolf, that led Ward to tell this story.

And it is that grief that speaks to a larger truth: that Ward’s brother and the other young men who died did matter, their lives did have value and those “who still live do what we must.” Like Ward’s mother, who plowed through hardship and disappointment and despair with resilience and resolve, those left behind “sleep and wake and fight and survive.”